Direction regulation of interface carrier transfer and enhanced photocatalytic oxygen activation over Z-scheme BiVO/Ag/AgCl for water purification.

Molecular oxygen activation is essential to the photocatalytic oxidation reaction, which is highly dependent on the construction of active sites and efficient charge transfer of photocatalysts. In this study, we constructed BiVO/Ag/AgCl Z-type heterojunction photocatalysts with significantly enhanced molecular oxygen activation capacity. The systematic characterization and analysis including X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations confirmed that the formation of efficient Z-type heterostructure could be attributed to the introduction of Ag nanoparticles (NPs), which regulated the electron transfer direction from BiVO to AgCl. Owing to the advantage of enhanced charge transfer efficiency, the O generation capacity of BiVO11/Ag/AgCl Z-scheme heterojunction was as high as 4.6 times that of pure BiVO. Consequently, BiVO/Ag/AgCl showed good degradation performance against tetracycline (TC), ciprofloxacin (CIP), ranitidine hydrochloride (RAN) and 2,4-dichlorophenoxyacetic acid (2,4-D) under visible light, and their degradation rates were 8.2 times, 5.9 times, 3.8 times and 11.9 times higher than those of BiVO, respectively. This study provides an effective and feasible strategy to design photocatalyst with improved molecular oxygen activation efficiency.